A. I think a pretty easy fix is for the 5th place finishers to play a 3 game series with each other for a small prize, perhaps one weeks worth of tv contract or merchandise or something. Or a scaling amount depending on div.
B. another option is that the regulation series does not generate arena money, that way the teams fighting to stay dont gain an advantage.
C. make a bracket for the bottom 8 teams, and run it just like the playoffs. the first round losers get demoted.
D. instead of having a relegation game, the bottom 4 teams automaticly get demoted.
E. relegation games are 1 game instead of 3.